Category Archives: Transhuman News

January 10, 2014

Brett Smith for redOrbit.com Your Universe Online

Finally, some good news for men, as a new study in PLOS Genetics has found that the human race may not be losing the Y chromosome after all. Some popular theories have posited that the male sex chromosome is destined to diminish and disappear.

The Y chromosome has lost 90 percent of the genes it once shared with the X chromosome, and some scientists have speculated that the Y chromosome will disappear in less than 5 million years, said study author Melissa A. Wilson Sayres, a post-doctoral evolutionary biologist at the University of California, Berkeley.

Some mammal species have lost their Y chromosome, yet still have the ability to sexually reproduce viable offspring fueling suspicions that the chromosome may not be essential in humans.

Our study demonstrates that the genes that have been maintained, and those that migrated from the X to the Y, are important, and the human Y is going to stick around for a long while, Wilson Sayres said.

Based the Y chromosome analysis of 16 men, researchers found genetic evidence of natural selection maintaining the chromosomes content, which has been shown to mostly play a role in male fertility. The researchers said the Y chromosomes diminutive size is a sign that it is stripped down to its 27 essential genes.

Melissas results are quite stunning. They show that because there is so much natural selection working on the Y chromosome, there has to be a lot more function on the chromosome than people previously thought, said co-author Rasmus Nielsen, UC Berkeley professor of integrative biology.

He added that the study will help advance estimates of humans evolutionary history that are done based on an analysis of the Y chromosome.

Melissa has shown that this strong negative selection natural selection to remove deleterious genes tends to make us think the dates are older than they actually are, which gives quite different estimates of our ancestors history, Nielsen said.

Continued here:
Study Shows Men Won’t Be Losing Their Y Chromosome Anytime Soon